well it could be a small reference to drugs but the point is that when you are somehow disconnected from reality (fainting or having seizures or a coma or even dreaming) it can bring about intense hallucinations

This guy was feeling sweepy while driving. He then realized that he wasn’t driving, but he was just holding a steering wheel. After that, a piano fell on him, putting him into a coma. Whilist in a coma, he had this dream on which he was flying. Without ever knowing he was in a coma, he said he never wanted to wake up, which meant he actually wanted to stay in a coma forever.